Healthy Ponds 52020 Pond Water Colorant/Spray Pattern Indicator Tablet, Reflection (Black); Treats 41,000 Gallons of Water or 10 Gallons SPI Solution Pond water colorants are essential once water clarity has been achieved using healthy ponds products Shades pond and limits sunlight penetration, reducing weeds and algae; within 24 hours pond will take on a beautiful appearance that reflects the sky Safe for fish, plants, pets and humans; made from certified food quality dyes Simply add the correct number of tablets for your pond size; one tablet treats up to 41,000 gallons Can also be used in a spray tank at a ratio of 1 tablet per 10 gallons of water to avoid overlap and missed areas when spraying turf, grass or gardens